Figure 2: Saccharomyces cerevisiae Proteome Pathways Affecting Fermentation. Nearly 2000 of the 6000 genes in S. cerevisiae have been mapped at some level to explore interactions among pairs of proteins to develop a yeast interactome [3]. Much of this data has been developed using yeast 2-hybrid analysis to explore even relatively transient unstable protein-protein interactions. This data has allowed some of these proteins with known functions to be associated with metabolic functions such as fermentation. It is likely that a majority of genes functioning in yeast affect this process either directly or indirectly. The size of each region is an approximate estimate of the percent of genes involved in the function noted among genes for which functions have been determined and was derived from published data [3]. In most cases functions are not exhaustive and further research will be required to develop this interactome further.